* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.box {

    position: fixed;

    left: 50%;
    top: 50px;
    border: 3px solid skyblue;
    width: 500px;
    height: 500px;
    text-align: center;
    transform: translateX(-50%);

}

.box h1 {
    color: pink;
    margin-top: 50px;
    margin-bottom: 50px;
}

.dis {
    display: none;
}



.topic {
    margin-bottom: 50px;
}

.answer {
    margin-bottom: 50px;
}

button {
    margin-bottom: 50px;
}